1st Place, Addition
Anonymous Hall transforms a 1960s medical library building into a vibrant center for the Graduate School of Arts and Sciences and a social hub for Dartmouth College’s north campus. The 33,000-square-foot renovation and addition remakes an extant building and reshapes its surrounding open space into a well-scaled and inviting extension of this historic Ivy League campus in Hanover, N.H.
PHOTOS: ALBERT VECERKA; BEFORE & DURING IMAGES: Leers Weinzapfel Associates
The renovated building has places for focus, collaboration, social interaction and informal gathering. A series of light-filled meeting spaces, lounges and niches are coupled with offices and teaching space at each level to accommodate diverse use. The main entry terrace under the addition connects the buildings lobby and a new cafe with a newly created lawn. The graduate student lounge on the lowest level opens out to a lowered and protected courtyard below a pedestrian bridge that connects to campus. Joined by a spiral stair overlooking the lawn, the building’s upper floors contain faculty offices, classrooms and places for student gathering. The uppermost level features a south-facing, planted rooftop terrace shaded by a photovoltaic canopy that looks south to Baker Tower and the college’s iconic campus.
Reorientation of the building and its dynamic façade to the south, as well as a series of new and redefined open green spaces finally connect Anonymous Hall and its north campus neighbors through the campus to the Dartmouth Green. A sweeping campus walk traffics those coming from the south and brings them past the new south lawn. A new entry axis connects the walk to the Anonymous Hall entry terrace and a new medical school entry. The 800-foot arcing walk then bridges the building’s lower terrace to land at the corner of the north quad, bounded by the building at its south edge.
Effective and economical reuse of existing buildings relies on maximizing what remains, successfully repurposing space for new and flexible use, and upfitting building and systems to reduce energy consumption. The renovation of Anonymous Hall tackles the challenge of reuse head-on and outperforms new construction.
Completely abated of hazardous materials and reclad with a high-performance enclosure, the existing building structure was retained and enhanced to meet modern codes. The reuse of its concrete foundations, three floors of cast-in-place concrete, and two floors of steel-framed structure significantly reduces demolition waste and eliminates the carbon-intensive new structure that would otherwise be required to be built in its place.
The story of reuse isn’t simply about carbon reduction. Retaining the structure is an important part of the building’s economic viability. The cost of demolishing and removing the existing building only to construct a replacement would be substantial. Through careful study, the program optimizes use within the existing structure, makes space to insert a new lateral system, and allows for the attachment of a lightweight and economical addition. Much of the building houses faculty and administrative offices mixed with analytical laboratory and seminar space. The efficient layout fits within the existing grid of columns, ringing shear cores of vertical circulation and building support. The result is a compact, efficient building with a reused structure that is economical without programmatic compromise.
Anonymous Hall’s upper floors are designed to be flexible, accommodating easy conversion of its offices and labs to other uses as needs change. The standardized radiant ceiling panels are readily reconfigurable to eliminate the need for replacement during reconfiguration, and the mechanical system has been designed to balance the system as occupancy changes. Daylight and occupancy sensors are wireless to further reduce rework. A perimeter hall and central connector further simplify changes while maintaining safe egress. Meeting and seminar spaces are designed to accommodate today’s use with pathways to permit changes in the future.
A backup generator provides emergency and standby power for critical building functions. Although not intended for extended occupation during a full and prolonged power outage, the inclusion of natural daylight and operable windows in all occupied spaces means the building and occupants can continue to use the building to bridge partial energy outages like brownouts or disruptions in campus energy.
The building’s economical design uses lightweight materials to further reduce the required investment for reuse. The new terra-cotta façade is thinner and lighter than traditional systems, reducing cost and materials within it and structure to support it. The south façade’s use of innovative vacuum insulated panels eliminates the need to build redundant structure behind the glass or to detail connections back to a traditional framing system. The radiant ceiling panels serve as the mechanism for heating and cooling, as well as the finished ceiling surface. Existing and new concrete are exposed to relay the life and reuse of the building rather than concealed with additional finishes. The floors and walls are clad in durable and maintainable resilient materials, and the exposed columns at the addition are integrally fireproofed to eliminate the need for additional column cladding.
The building focuses energy-efficiency improvements around several effective strategies, matching envelope and systems to the building and place. These consist of:
- A highly insulated terra-cotta façade with optimally proportioned triple-glazed windows and overshadowing at three sides.
- An innovative integrally shaded insulated glass façade system facing south to form an efficient envelope.
- Hydronic heating and cooling using responsive radiant ceiling panels with dedicated outside air and natural ventilation that are a match to the constraints of the existing building and the efficient façade.
- Reducing embodied carbon compared to typical new construction by:
- Reusing the concrete and steel structure. The result is a reduction of 1,237 metric tons of CO2 with the reuse of 20,000 cubic feet of concrete alone.
- Including onsite energy generation with a 67-kilowatt photovoltaic canopy that reduces net energy use and operational carbon.
Situated in a cold New Hampshire climate, the choice of high R-value terra-cotta-clad walls, triple-glazed windows, south-facing glass with an expanded metal interlayer to limit summer sun and onsite electrical generation create a building with low embodied energy that approaches net zero energy use. This low operational carbon building is further enhanced by reusing the existing 1960s concrete and steel structure, thereby reducing embodied carbon.
Complementing its energy efficiency, the building’s transformation is made apparent to users and visitors alike through difference and absence. The extraordinary quiet in the interior spaces alludes to its highly insulated, triple-glazed skin and radiant heating and cooling. The light quality and comfort in spaces at the south façade defy the intense sun incident on the glass. The “just right” light levels in the offices and classrooms indicate the sensors and controls are optimized. A sophisticated set of sensors and controls combined with dedicated outside air and natural ventilation in each space also improve indoor air quality, occupant comfort and connect to nature. From the outside, the ever-changing disposition of the south-facing glass reveals its purpose. It reflects at times, diffuses at times and transitions from translucent to transparent as daylight fades.
The COVID-19 pandemic forced the college to close for residential learning soon into the building’s first months of operation. Anonymous Hall operated with limited café hours, no in-person classes and only a few users. Many of its exterior and interior public spaces, meant to enliven the north campus, now welcome the return of student activity.
METAMORPHOSIS AWARD WINNER and ARCHITECT: Leers Weinzapfel Associates
- Josiah Stevenson, FAIA, LEED AP, principal
- Kevin Bell, AIA, project manager/ project architect
- Juliet Chun
- Jennifer Hardy
- Langer Hsu
- Taehoon Lee
- Zoyi Lin
- Ashley Rao
- Bobby Main
MEP-FP AND LIGHTING ENGINEER: van Zelm Heywood & Shadford Inc.
STRUCTURAL ENGINEER: LeMessurier
HARDWARE: Robbie McCabe Consulting
COST ESTIMATING: Faithful+Gould Inc.
CODE: Howe Engineers Inc.
SUSTAINABLE DESIGN: Atelier Ten
FAÇADE GLASS: Okalux North America
WINDOW GLASS: Vitro Architectural Glass
CURTAINWALL: Wausau Window and Wall Systems
WINDOW AUTOMATION: WindowMaster
INTERIOR SHADES: Mecho
TERRA-COTTA FAÇADE: Terra5 from Cladding Corp.
FAÇADE ATTACHMENT SYSTEM: Alpha Vci from Eco Cladding
BUILDING CONTROLS: Johnson Controls
RADIANT CEILING PANELS: Steel Ceilings from Armstrong Ceiling & Wall Solutions
LIGHTING CONTROLS: Lutron